Alaska Geoid Heights (GEOID96)
This 2' x 4' geoid height grid for Alaska is distributed as a GEOID96 model. The computation used 1.1 million terrestrial and marine gravity data held in the National Geodetic Survey gravity data base in July 1996 These data were augmented by gravity data contributions from NGA (former National Imagery and Mapping Agency (former Defence Mapping Agency)). By means of a Fast Fourier Transform (FFT) technique, high frequency corrections were made to an underlying EGM96 geopotential model through a remove, compute, and restore process. The gravity values are based on the International Gravity Standardization Net 1971 (IGSN71). The geoid heights are referred to the Geodetic Reference System 1980 (GRS80) ellipsoid. Unlike the grid for the conterminous United States, this GEOID96 grid does not incorporate GPS on leveled benchmarks. This model is a gravimetric geoid in a geocentric, ITRF94(1996.0) reference frame. It is necessary to subtract 12.0 cm from these values to obtain the geoid undulation between the best-fit global geopotential surface and the GRS80 ellipsoid (both expressed in a tide free system). Additional information is available at: http://www.ngs.noaa.gov/GEOID/geoid.html We are particularly grateful to NGA (former National Imagery and Mapping Agency) for their assistance and their data contributions.
Dataset Citation
- Use Constraints: If you use this data, please cite the National Geophysical Data Center and the originator of the data.
Dataset Identifiers
- ID not available.
ISO 19115-2 Metadata
gov.noaa.ngdc.mgg.geophysics:G01423
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Ordering Instructions | Ordering Instructions: Prepay by check, money order or bank card. There is a standard handling charge, with additional costs for special handling. Orders may be placed via fax, email, regular mail or telephone. Custom Order Process: Contact Data Center for information. |
Distributor | User Services DOC/NOAA/NESDIS/NCEI > National Centers for Environmental Information, NESDIS, NOAA, U.S. Department of Commerce 303-497-6826 ngdc.info@noaa.gov |
Dataset Point of Contact | Brian Meyer NOAA National Centers for Environmental Information 303-497-6125 Brian.Meyer@noaa.gov |
Time Period | Unknown to Unknown |
Spatial Reference System | urn:ogc:def:crs:EPSG::5715 |
Spatial Bounding Box Coordinates |
West: -180
East: -126
South: 49
North: 72
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Documentation links not available. |
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Edition | 1999 Edition |
Dataset Progress Status | Complete - production of the data has been completed |
Data Update Frequency | Irregular |
Supplemental Information | Note that for the Alaska Geoid96 data the West Bounding Coordinate is actually -188 degrees. |
Purpose | To provide easy access to global and regional gravity data and related models for scientific studies. |
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Global Change Master Directory (GCMD) Science Keywords
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Global Change Master Directory (GCMD) Location Keywords
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Global Change Master Directory (GCMD) Project Keywords
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Last Modified: 2017-09-25
For questions about the information on this page, please email: Brian.Meyer@noaa.gov
For questions about the information on this page, please email: Brian.Meyer@noaa.gov